Several passengers aboard downed Malaysian Airlines flight MH17 were headed to the 20th International AIDS Conference taking place in Melbourne, Australia when the plane crashed, according to reports.

On Friday, the International AIDS Society confirmed in a statement [PDF] that "a number of colleagues and friends" were aboard the plane, although it did not state an exact figure.

In prepared remarks that morning, however, US President Barack Obama appeared to confirm reports that nearly a third of the passengers were scientists, health workers, and activists headed for the conference.

"On board Malaysian Airlines flight MH17 there were apparently nearly 100* researchers and advocates traveling to an international conference in Australia dedicated to combating AIDS/HIV," the President said. "These were men and women who had dedicated their own lives to saving the lives of others and they were taken from us in a senseless act of violence."

The Boeing 777 was en route from Amsterdam to Kuala Lumpur on Thursday when it was struck by a surface-to-air missile over a disputed region of eastern Ukraine. All 298 people aboard were killed in the resulting crash.

As first reported by the Sydney Morning Herald, among those confirmed dead was Dutch HIV researcher Dr Joep Lange. A former president of the International AIDS Society, Lange was one of the earliest proponents of combination therapy using multiple antiretroviral drugs for management of HIV/AIDS. He was also a staunch advocate of the availability of affordable HIV/AIDS medication for the poor, particularly in Africa.

Other confirmed victims of the incident include Pim de Kuijer, a parliamentary lobbyist for the Dutch health organization Stop AIDS Now!; and Glenn Thomas, a spokesman for the World Health Organization.

A full list of the passengers that were aboard the plane has yet to be released.

"We are bracing ourselves to hear of the deaths of others who worked in the AIDS response as their names are officially released," Michel Sidibé, executive director of United Nations advocacy group UNAIDS, said in a statement. "The UNAIDS family is in deep shock. Our hearts go out to the families of all the victims of this tragic crash. The deaths of so many committed people working against HIV will be a great loss for the AIDS response."

Although the losses weigh heavily over this year's International AIDS Conference, however, organizers say the MH17 incident will not interrupt the proceedings. The conference is expecting some 12,000 attendees.

"In recognition of our colleagues' dedication to the fight against HIV/AIDS, the conference will go ahead as planned and will include opportunities to reflect and remember those we have lost," a spokesperson for the International AIDS Society said in a statement [PDF]. ®